1. Field of the Invention
This invention relates to the so-called hot isostatic pressing system (hereinafter referred to simply as "HIP" for brevity) generally used for sintering powdery material, and more particularly to a modular HIP system which can realize a marked improvement in productivity.
2. Description of the Prior Art
Various techniques have thus far been developed in the sphere of the hot isostatic compaction process wherein a workpiece is processed in a high pressure and temperature gas atmosphere for sintering or for other treatment in a processing chamber of a pressure cylinder with a closure plug or plugs at an open end or ends thereof and having a heat insulating mantle provided in the processing chamber along with a heater located on the inner side of the mantle. For example, in a case where the HIP techniques are resorted to for shaping and sintering a powdery material, it becomes possible to attain a higher densification at lower temperatures, a density close to the theoretical value and to secure a finer and more uniform texture as compared with the conventional sintering means, coupled with various advantages such as improvements in the mechanical and physical properties of the powder, the feasibility of shaping powder materials unsuitable for die forming, the ability to form large products without the limitation as imposed by the press capacity in the case of ordinary die forming presses, the shaping of composite materials such as of a metal and ceramics, an improvement in the yield of the material, etc. In addition to the shaping and sintering of powder materials, the HIP process can be utilized for other purposes.
In spite of the above-mentioned various advantages, the HIP process has a serious problem that it is extremely low in productivity, so that there have thus far been made various attempts to shorten the cycle time period and to improve the efficiency of operation and use of the HIP system as a whole, including Applicant's Japanese Laid-Open Patent Specification No. 51-124610 disclosing an improved HIP method and a HIP system therefor.